Electric circuit interrupter

ABSTRACT

An electric circuit interrupter which is primarily adapted for use in conjunction with an electric fuse or cutout includes a housing structure comprising an inner tubular housing element of insulating material, a pair of outer tubular housing elements of insulating material telescopically mounted respectively about opposite ends of the inner tubular housing element and movable relative to each other and to said inner housing element together with a pair of relatively movable contacts one of which is fixedly mounted relative to one of the outer housing elements. An opening spring is interposed between the inner housing element and the other of said outer elements and biases the contacts toward open circuit condition while a closing spring is interposed between the inner housing element and said one outer housing element and biases the contacts toward closed condition. The closing spring is energized by the opening spring during a contact opening operation. The telescoping elements are interrelated so as normally to exclude moisture due to atmospheric precipitation from the interior of the housing and the housing elements also serve to isolate the conductive parts disposed within the housing from the biasing springs.

United States Patent 91 Jackson, Jr.

[ Apr. 8, 1975 [75] Inventor:

[52] US, Cl ..200/163; ZOO/146 R; 200/16 C; ZOO/321; ZOO/323 [51] Int.Cl. I-I0lh 1/38 [58] Field of Search ZOO/146, 163, 16 B, 16 C, 200/151,321, 323. 290

[56] References Cited UNITED STATES PATENTS 2,785,319 3/1957 Simpson eta1 ZOO/163 R 3,259,726 7/1966 Rueffcr 200/151 R Primary Examiner-RobertS. Macon Attorney, Agent, or FirmWalter M. Rodgers [57] ABSTRACT Anelectric circuit interrupter which is primarily adapted for use inconjunction with an electric fuse or cutout includes a housing structurecomprising an inner tubular housing element of insulating material, apair of outer tubular housing elements of insulating materialtelescopically mounted respectively about opposite ends of the innertubular housing element and movable relative to each other and to saidinner housing element together with a pair of relatively movablecontacts one of which is fixedly mounted relative to one of the outerhousing elements. An opening spring is interposed between the innerhousing element and the other of said outer elements and biases thecontacts toward open circuit condition while a closing spring isinterposed between the inner housing element and said one outer housingelement and biases the contacts toward closed condition. The closingspring is energized by the opening spring during a contact openingoperation. The telescoping elements are interrelated so as normally toexclude moisture due to atmospheric precipitation from the interior ofthe housing and the housing elements also serve to isolate theconductive parts disposed within the housing from the biasing springs.

14 Claims, 9 Drawing Figures szema m PATENTEDAPR 81975 @QQQQ 1 ELECTRICCIRCUIT INTERRUPTER Auxiliary circuit interrupters for use inconjunction with electric fuses and cutouts are normally connected inparallel circuit relation to a pair of separable contact elementsconstituting portions of the fuse or cutout and such contacting elementsnormally are opened initially followed by subsequent opening of thecontacts of the auxiliary interrupter, the auxiliary interrupter beingwell adapted to interrupt and extinguish an electric arc. Such auxiliaryinterrupters ordinarily must be of compact and unitary construction andfor this reason may be arranged so the current to be interrupted istransmitted through a biasing spring which may serve quickly to separatethe contacts once a circuit interrupting operation is initiated. In sucha device, a series of operations which require a biasing spring toconduct substantial currents may impair the characteristics of thespring. Furthermore it is frequently the practice to construct auxiliaryinterrupters in such manner that'conducting elements are exposed duringa circuit interrupting operation and thus constitute a hazard to theoperator. In known auxiliary interrupters, it is sometimes the practiceto energize the opening spring and the closing spring manually andsimultaneously thus requiring a substantial operating force which mustbe imparted to the operating elements by an operator usually through theinstrumentality of a hook stick.

According to the present invention an auxiliary circuit interrupter isprovided in which closing an opening springs are shielded from theconducting elements and from atmosphere and in which the conductingparts are fully enclosed. Furthermore, according to the invention, theclosing spring is energized by the opening spring during the laterstages of a circuit interrupting operation. More specifically anauxiliary interrupter constructed according to one form of the inventionmay comprise an inner tubular hollow housing element of insulatingmaterial about which a pair of outer tubular housing elements formed ofinsulating material are telescopically disposed with one outer elementsurrounding one end of the inner housing element and with the otherouter element surrounding the other end of the inner element and onecontact of a pair of relatively movable contacts is mounted in fixedrelation within the inner housing element and the other contact ismounted in fixed relation within one of the outer housing elements.Preferably the telescoping housing elements are constructed and arrangedso as to exclude atmospheric precipitation from inside the interrupterhousing structure.

For a better understanding of the invention reference may be had to thefollowing detailed description taken in conjunction with theaccompanying drawings in which FIG. 1 is an overall side view of anelectric cutout on which an auxiliary circuit interrupter constructedaccording to the invention is mounted, the cutout and interrupter beingshown in closed circuit condition; FIG. 2 is an enlarged view partiallyin section of a portion of the apparatus shown in FIG. 1 and taken alongthe line designated 2-2 in FIG. 1; FIG. 3 is a view similar to FIG. 1but showing the cutout in its open circuit position; FIG. 4 is a topview of a mounting racket by which the auxiliary interrupter is mountedon the sleet shield of the cutout; FIG. 5 is a side view of FIG. 4 takenalong the line designated 5-5 in FIG. 4; FIG. 6 is a side view of theupper portion of the cutout and interrupter depicted in FIGS. 1 and 3ane which represents the upper contact structure of the interrupter andcutout in partially opened condition; FIG. 7 is a cross-sectional viewof the auxiliary interrupter showing the parts in their closed circuitpositions; FIG. 8 is a view similar to FIG. 7 but showing the parts inthe positions which they occupy after a circuit interrupting operationhas been initiated but before contact separation takes place and inwhich FIG. 9 is a view similar to FIGS. 7 and 8 and which depicts thecontacts after separation but before the relatively movable conductingparts have reached their maximum degree of separation.

In the drawings the numeral 1 designates a conventional insulatorsupported by a conventional insulator mounting bracket designated by thenumeral 2. Of course mounting bracket 2 is secured to any suitablesupporting structure such as a power line pole or cross arm inconventional fashion. Secured atop insulator l is the top hardwarestructure of a conventional contact generally designated by the numeral3 on which line terminal 4 is mounted. Bottom hardware structure of thecutout is generally designated by the numeral 5 and is secured to thelower end of insulator 2 in conventional fashion and supports lineterminal 6. A fuse holder generally designated by the numeral 7interconnects the hardware structures 3 and 5 in conventional fashion.An auxiliary interrupter generally designated by the numeral 8 isconstructed according to this invention and is mounted by means ofmounting band 9 about the housing of interrupter 8 and which in turn issecured to mounting bracket 10 by bolts 11 and 12 as best shown in FIG.4. Mounting bracket 10 is secured by bolts or rivets 13 to the sleethood 14 which is of conventional construction. Line terminal 4 iselectrically connected with sleet hood 14 and may be formed integrallytherewith. Conductor 15 interconnects the upper lefthand terminal ofauxiliary interrupter 8 with the mounting bracket 10 by suitable meanssuch as by bolt 11.

At the opposite end of the auxiliary interrupter 8 conducting latch 16is arranged for cooperative engagement with auxiliary contact 17 mountedby means of transverse conducting element 18 to the upper metallicconducting collar 19 of the fuse holder 7. A sleet hood 20 is disposedabove contact 16. In parallel with the circuit through the auxiliaryinterrupter 8 is the sleet hood 14 which is provided with a yieldablecontact 21 and a yieldable latch 22 of conventional construction. Whenthe parts are in their closed positions as shown in FIG. 1, the uppercontact 23 forming an integral part of collar 19 of the fuse holder isdisposed in secure contacting engagement with contact 21 and is held inthis position behind the latch 22. Dispostable cap 24 is mounted atopthe collar 19 in conventional fashion and a pivotally mounted latchrelease element 25 is arranged for engagement with a hook stick by wayof the aperture 26 formed therein so that downward movement of the righthand end of latch 25 elevates latch 22 and releases the contact 23 sothat this contact as well as the auxiliary contact 17 may move towardthe right and generally clockwise from the position depicted in FIG. 1to the fully open position depicted in FIG. 3. The fusible element isnot shown but is disposed within the fuse tube 711 and is terminated byfuse link extension 33 to the lower hardware structure 5.

Lower tube casting 27 is secured about the lower end of fuse tube 7a andis pivoted at 28 to hinge element 29 provided with trunions 30 rotatablewithin a pair of spaced apart jaws 31 which form integral portions ofconducting element 32 which is secured in known manner to the lower endof insulator 1 and on which terminal 6 is mounted.

The fuse link extension 33 is secured as by a thumb screw 34 in securecontact relation to the hinge element 29 in a manner well known in theart.

A suitable aperture 35 is formed in lower casting 27 in conventionalfashion.

For the purpose of relieving the fuse link and its extension 33 from asubstantial portion of the weight of the fuse holder 7 and of the biasof contact springs which are conventional construction, the latchingelement designated by the numeral 36 may be provided. This latch elementis pivotally mounted at 37 on the hinge element 29 and is provided withan offset portion 38 which as shown in FIG. 1 is disposed adjacent pin39 mounted on a pair of spaces ears 40 when the fuseholder is in fusedposition. This with the parts occupying the positions depicted in FIG.1, a substantial part of the weight of the fuse holder 7 and of thepressure due to the contact springs is taken by the latch 36.

In order to facilitate an opening operation and to aid in ejecting thelower end of the fuse link and of extension 33 from the lower end of thefuse tube 7a, a biasing spring is provided and is designated by thenumeral 41 as best shown in FIG. 2. The biasing spring has one end 42biased against latch 36. Tab 44 on latch 36 contains the leg 42preventing its slipping off the latch. End portion 43 of biasing spring41 is captured underneath the portion 46 of hinge 29 so as to urge thelatch 36 toward rotation in a clockwise direction as viewed in FIGS. 1and 3 about its pivot 37.

With the parts occupying the positions depicted in FIG. 1, an overloadthrough the device causes the fuse link tomelt and allows the fuseholder and all parts associated therewith including auxiliary contact 17and transverse conductor 18 to swing in a generally downward andclockwise direction into the position depicted in FIG. 3. Of course suchmotion is facilitated by rotation of the hinge element 29 about thetrunions 30 and is accompanied by rotation of the fuse holder 7 aboutits pivot 28 and simultaneous rotation of the latch 36 about its pivot37 so that when the circuit is open the parts occupy the positionsdepicted in FIG. 3.

Should the circuit through the cutout be live, the current flowing insuch circuit may be interrupted by the arrangement shown in the drawingsby simply inserting a hook stick into the aperture 26 and by thenexerting a downward pull thereon. Such an operation releases latch 22from contact 23 and allows the contact 23 to disengage contact 21 whilecontact 17 remains in contacting relation with the lower latch contact16 of the auxiliary interrupter 8. Continued swinging movement of thefuse holder in a generally clockwise direction about the trunions 30subsequently results in withdrawal of the lower latch contact 16 fromthe interrupter 8 and subsequently the circuit is interrupted by theauxiliary interrupter 8.

The auxiliary interrupter constructed according to this invention isbest shown in detail in FIGS. 7, 8 and 9 and comprises housing structureincluding an inner hollow tubular housing element of insulating materialdesignated by the numeral 50 together with one hollow outer tubularhousing. element designated by the numeral 51 and telescopicallydisposed about the lower end of inner tube together with another hollowouter tubular element constructed of insulating material and designatedby the numeral 52 disposed about the upper end of inner tube 50 intelescoping relation therewith. An upper outwardly extending flangeelement 53 is secured to the upper end of inner tube 50 and a lowerflange 54 projects outwardly and is secured to the lower end of innertube 50. A closure cap 55 is fixedly secured about the upper end ofouter insulating tubular element 52 in any suitable manner while a lowerclosure cap 56 is suitably secured about the lower end of outer housingelement 51. An inwardly projecting flange 57 is formed about the lowerend of outer housing element 52 while an inwardly projecting flange 58is integrally formed with the upper end of outer housing element 51.

The circuit through the interrupter comprises the lead-in terminal 15,the flexible helical conductor 59 rigidly secured in contacting relationto the contact ferrule 60 on which a plurality of contact fingers 61 aremounted, and the stabber contact 62 having shoulder portion 63 which isgripped when in closed position by the inwardly projecting portions 64of the contact fingers 61 so as releasably to latch the contacts closed.At its lower end, stabber 62 is connected with conducting latch 16 whichas pointed out above is arranged to cooperate with auxiliary contact 17to complete a circuit from terminal 4 to the upper conducting elementsof the fuse holder 7.

To aid in effecting rapid separation ofthe contacts 61 and 62, operatingbiasing means in the form of an opening spring 65 is interposed betweenflange 53 on inner tube 50 and internal flange 57 formed on externaltube 52 and between tubes 50 and 52.

For the purpose of reclosing the interrupter conducting parts and forrestoring the housing elements to their normal closed positionsfollowing a circuit interrupting operation, operating biasing means inthe form of a closing spring designated by the numeral 66 is providedand cooperates with the outwardly projecting flange 54 on the lower endof inner tube 50 and the inwardly projecting flange 58 formed at theupper end of outer housing tube 51. Closing spring 66 is capturedbetween tubes 50 and 51. Both springs 65 and 66 are compression typesprings and are isolated from the conducting parts and are shielded fromatmospheric conditions.

Contact latch 16 is provided with a latch surface 67 which cooperateswith auxiliary contact 17 and stabber.

62 is secured to latch 16 and cap 56 by pin 68. Since cap 56 is securedto outer tube 51, it is apparent that contact 62 is fixed in relation toouter housing element 51. A shoulder 69 is formed in outer tube 52 andis disposed for engagement by flange 53 of tube 50. Furrule 60 is fixedin position relative to tube 50 by virtue of flange 70 which is integralwith inner tube 50 and which is captured between flanges 71 and 72 onferrule 60. Stabber 62 is surrounded by gas emitting elements 73 and gasis exhausted through ports 74 in cap 56.

In order to effect a circuit interrupting operation via the auxiliaryinterrupter 8, a hook stick is inserted into opening 26 and a downwardpull exerted thereon. This operation separates upper contact 23 of thefuse holder from its associated contact 21 as explained. Subsequentlyauxiliary contact 17 engaged behind shoulder 67 of conducting contactlatch 16 secured to the ward movement of the lower cap 56 and of theouter housing element 51 since these parts are securely affixed to thelower end of the stabber by any suitable means such as by pins 68. Sincethe contact fingers 61 at their ports 64 securely grip the recessedportion 63 f the stabber 62, the finger contacts 61, the ferrule 60 andthe inner tubular housing element 50 are drawn downwardly until suchtime as the outwardly projecting flange 53 engages the inwardlyprojecting shoulder 69 formed in the outer housing element 52. When thisoccurs, continued force applied to the stabber 62 of the order ofmagnitude of thirty pounds or. so causes separation of the shoulderportion 63 of stabber 62 from the gripping portion 64 of the fingercontacts 61. Immediately following separation ofthese parts, the openingspring 65 immediately urges the inner tubular housing element 50, theferrule 60 and contact fingers 61 upwardly and quickly draws an arcbetween the finger contacts 61 and the stabber 62 which arc isextinguished by are extinguishing structure generally designated by thenumeral 73 and which is of conventional construction. The gases andother products ofinterruption may be vented to atmosphere through ports74 formed in cap 56.

After interruption, the auxiliary contact 17 releases the surface 67 ofthe conducting latch 16 at some point during its clockwise rotationabout the trunions 30. When such separation occurs, the parts which theymay occupy a position such as that indicated in FIG. 9 are restored tothe condition depicted in FIG. 7 by means of the closing spring 66 whichas will be obvious is charged during the contact separating movement ofthe contacts imparted by the opening spring 65. Thus the closing spring66 is never biased until an opening operation begins and then the majorportion of its energy is imparted thereto during the later stages of acontact separating operation. Of course opening spring 65 is arelatively strong spring compared to closing spring 66 which sometimesis referred to as a reclosing spring.

From the above description and from the drawings, it is apparent thatatno time is the opening spring 65 or the closing spring 66 exposed tothe flow of current or even to the are which is drawn by the arcingcontacts since these springs are always interposed between the innerhousing element 50 and the outer housing elements 51 or 52. Furthermorenone of the conducting parts is exposed in such manner as to constitutea hazard to an operator since the live parts are always completelyenclosedwithin the insulating inner and outer tubular housing elements.Furthermore since the reclosing spring need only be a weak spring, andsince according to the invention this spring is energized during thelater stages of an opening operation by the relatively strong openingspring, the force required to withdraw the stabber 62 from its closedcircuit condition to its open circuit condition as represented in FIG. 9is less than might otherwise be required as for example in thosestructures where both an opening and a closing spring are chargedmanually by an operator during a circuit opening operation.

From FIGS. 4 and it is apparent that the mounting bracket 10 isrelatively rigid in a ,vertical direction due to the fact that thematerial from which it is formed is substantially larger in its verticaldimension as shown in FIG. 5 than in its horizontal dimension as shownfor ex ample in FIG. 4. Thus the mounting bracket constitutes a yieldable mounting which accommodates limited 'sidevvise' movement of theinterrupter but which virtually precludes substantial vertical movementof the interrupter. Thus when thelcircuit is being opened manually as bymeans ofa hook stick, inherent flexibility prevents or reducessubstantially any tendency of the relatively movable parts to bindshould the operator exert an opening force at an angle to the normalplane of swinging movement of the fuse holder. I

The embodiments of the invention in which an exclusive property orprivilege is claimed as defined as follows:

1. An electric circuit interrupter comprising housing structure, a pairof relatively movable contacts disposed within said housing structureand normally latched closed, opening biasing means for separating saidcontacts upon release of said contacts from their latched closedcondition, and closing biasing means energized by said opening biasingmeans for imparting relative closing movement to said contacts, theopening force imparted to said contacts by said opening biasing meanssubstantially exceeding the closing force imparted to said contacts bysaid closing biasing means.

2. An electric circuit interrupter comprising an inner tubular housingelement ofinsulating material, a pair of outer tubular housing elementsformed of insulating material and telescopically mounted respectivelyabout opposite ends of said inner tubular housing element, said outerhousing elements being movable relative to each other and to said innerhousing element, a pair of relatively movable contacts one of which ismounted in fixed relation to said inner housing element and the other ofwhich is mounted in fixed relation to only one of asid outer housingelements, and a pair of operating springs interposed respectivelybetween said inner tubular housing element and said pair of outertubular housing elements, said springs being isolated from said contactsand from atmosphere by said housing elements.

3. An electric circuit interrupter according to claim 2 wherein one ofsaid springs is interposed between said inner housing element and saidone outer housing element and is effective to bias said contacts towardclosed positions.

4. An electric circuit interrupter according to claim 2 wherein one ofsaid springs is interposed between said inner housing element and theother of said outer housing elements and is effective to bias saidcontacts toward open circuit condition.

5. An electric circuit interrupter according to claim 2 wherein an endportion of one of said outer housing elements is disposed within theadjacent end portion of the other of said outer housing elements andwherein said other outer housing element is disposed at a level abovesaid one outer housing element when said contacts are closed so as toshield the interior of the housing from atmosphere precipitation.

6. An electric circuit interrupter according to claim 2 wherein saidinner housing element is provided with outwardly projecting flanges atits ends and wherein each of said outer housing elements is providedwith an inwardly projecting flange at its inner end.

7. An electric circuit interrupter according to claim 5 wherein aclosing spring is interposed between the flange on said one of saidouter housing elements and the adjacent flange on said inner housingelement.

8. An electric circuit interrupter according to claim 7 wherein anopening spring is interposed between the other flange on said innerhousing element and the flange on the other of said outer housingelements.

9. An electric circuit interrupter according to claim 7 wherein saidclosing spring is energized by said opening spring during a circuitinterrupting operation.

10. An electric circuit interrupter according to claim 2 wherein theother of said outer housing elements is mounted on and supported by afixedly mounted mounting bracket which is somewhat yieldable in adirection transverse to the axis of the interrupter.

11. An electric circuit interrupter comprising housing structure, a pairof relatively movable contacts dis- .posed within said housing structureand normally latched closed, opening biasing means for separating saidcontacts upon release of said contacts from their latched closedcondition, and closing biasing means energized by said opening biasingmeans for imparting relative closing movement to said contacts.

12. An interrupter according to claim 11 wherein said closing biasingmeans is energized by said opening biasing means during the final stagesof a contact opening operation.

13. An interrupter according to claim 11 wherein said housing structureis arranged to isolate said opening and said closing biasing means fromsaid contacts.

14. An interrupter according to claim 11 wherein said housing structureis arranged to isolate said opening and said closing biasing means fromatmosphere

1. An electric circuit interrupter comprising housing structure, a pairof relatively movable contacts disposed within said housing structureand normally latched closed, opening biasing means for separating saidcontacts upon release of said contacts from their latched closedcondition, and closing biasing means energized by said opening biasingmeans for imparting relative closing movement to said contacts, theopening force imparted to said contacts by said opening biasing meanssubstantially exceeding the closing force imparted to said contacts bysaid closing biasing means.
 2. An electric circuit interruptercomprising an inner tubular housing element of insulating material, apair of outer tubular housing elements formed of insulating material andtelescopically mounted respectively about opposite ends of said innertubular housing element, said outer housing elements being movablerelative to each other and to said inner housing element, a pair ofrelatively movable contacts one of which is mounted in fixed relation tosaid inner housing element and the other of which is mounted in fixedrelation to only one of asid outer housing elements, and a pair ofoperating springs interposed respectively between said inner tubularhousing element and said pair of outer tubular housing elements, saidsprings being isolated from said contacts and from atmosphere by saidhousing elements.
 3. An electric circuit interrupter according to claim2 wherein one of said springs is interposed between said inner housingelement and said one outer housing element and is effective to bias saidcontacts toward closed positions.
 4. An electric circuit interrupteraccording to claim 2 wherein one of said springs is interposed betweensaid inner housing element and the other of said outer housing elementsand is effective to bias said contacts toward open circuit condition. 5.An electric circuit interrupter according to claim 2 wherein an endportion of one of said outer housing elements is disposed within theadjacent end portion of the other of said outer housing elements andwherein said other outer housing element is disposed at a level abovesaid one outer housing element when said contacts are closed so as toshield the interior of the housing from atmosphere precipitation.
 6. Anelectric circuit interrupter according to claim 2 wherein said innerhousing element is provided with outwardly projecting flanges at itsends and wherein each of said outer housing elements is provided with aninwardly projecting flange at its inner end.
 7. An electric circuitinterrupter according to claim 5 wherein a closing spring is interposedbetween the flange on said one of said outer housing elements and theadjacent flange on said inner housing element.
 8. An electric circuitinterrupter according to claim 7 wherein an opening spring is interposedbetween the other flange on said inner housing element and the flange onthe other of said outer housing elements.
 9. An electric circuitinterrupter according to claim 7 wherein said closing spring isenergized by said opening spring during a circuit interruptingoperation.
 10. An electric circuit interrupter according to claim 2wherein the other of said outer housing elements is mounted on andsupported by a fixedly mounted mounting bracket which is somewhatyieldable in a direction transverse to the axis of the interrupter. 11.An electric circuit interrupter comprising housing structure, a pair ofrelatively movable contacts disposed within said housing structure andnormally latched closed, opening biasing means for separating saidcontacts upon release of said contacts from their latched closedcondition, and closing biasing means energized by said opening biasingmeans for imparting relative closing movement to said contacts.
 12. Aninterrupter according to claim 11 wherein said closing biasing means isenergized by said opening biasing means during the final stages of acontact opening operation.
 13. An interrupter according to claim 11wherein said housing structure is arranged to isolate said opening andsaid closing biasing means from said contacts.
 14. An interrupteraccording to claim 11 wherein said housing structure is arranged toisolate said opening and said closing biasing means from atmosphere